Method for the sand control of a well



Dec. 9, 1969 G. o. suMAN, JR 3,482,629

. METHOD FOR THE SAND CONTROL OF A WELL Filed June 20 1968 2 Sheets-Sheet l FIG.2

VIIIIIIIIIM GEORGE O. SUMAN, JR.

HIS ATTORNEY Dec. 9, 1969 G. o. suMAN, JR 3,482,629

METHOD FOR THE SAND CONTROL OE A wELL Filed June 20, 1968 2 Sheets-Sheet 2 FIG.

INVENTOR GEORGE O. SUMAN,JR BY ew) HIS ATTORNEY United States Patent O 3,482,629 METHOD FOR THE SAND CONTROL OF A WELL George O. Suman, Jr., Metairie, La., assignor to Shell Oil Company, New York, N.Y., a corporation of Delaware Filed June 20, 1968, Ser. No. 738,532 Int. Cl. B21b 43/02, 47/10 U.S. Cl. 166-255 10 Claims ABSTRACT OF THE DISCLOSURE A method for controlling sand in a well having a tubing string and a sand control device mounted therein. A substantial increase in the production of sand flowing into the well is observed thereby indicating a damaged sand control device. The exact location of the damage is ascertained and a repair patch is run down the tubing string and expanded against the damaged portion of the device, thereby sealing the damaged portion.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates generally to screens perforate liners, or other devices having small orifices for allowing fluids to enter a well while keeping sand out of water, oilor gas-producing wells; and more especially to a method for repairing damaged sand control devices.

Description of the prior art In unconsolidated sand formations, the ow of oil, water and/or gas into the casing would carry with it a certain percentage of loose particles of sand if they were not restricted or removed by a properly sized screen or similar sand control device. The fluid ow carries these particles to the casing where the screen stops the particles from entering the casing. Of course, some extremely fine particles are usually carried upwardly in a well tubing by the production uid fiowing from the well, this results only in cases where there is a relatively high velocity of uid flow. Since a quantity of sand entering and settling in the casing eventually plugs up the well and shuts off production, various types of sand control devices have been developed in order to keep sand out of the casing.

Sand control devices of known types have generally been made from metals which have a tendency to corrode, and/ or erode, and to plug up the openings in the devices when immersed over long periods of time in the well due to the reaction with various chemicals or compounds encountered in wells. The result of such corrosion and erosion is in some cases to gradually close or, in other cases, to enlarge the holes through which the oil and gas pass, thus making it easier for sand to enter the casing.

Thus, sand control is frequently lost in oil or gas wells when a hole or holes are eroded in wire-wrapped screens, inner liners, liners and casing sometimes used in conjunction with gravel packing operations.

Normal techniques for repairing lost sand control in wells having damaged sand control devices mounted therein is to remove and replace the gravel pack and/ or screen installation (i.e., the sand control device) or to inject or reinject plastic consolidation materials through the failed production interval pipe. These techniques require the use of reconditioning or workover rigs and may be exceedingly expensive, especially with regard to offshore wells. Expensive fishing jobs recovering failed screens and liners may result in attempts to remove and replace the damaged sand control device; injection or reinjection of consolidation materials is generally limited to relatively short perforated intervals.

3,482,629 Patented Dec. 9, 1969 p ICC It is an object of this invention to provide a method for repairing a damaged sand control device without the necessity of removing the device from the well.

It is a further object of this invention to provide a method of repairing a damaged sand control device in a Iwell which may be accomplished relatively inexpensively thereby substantially reducing repair costs in wells which have suffered failure of wire-wrapped screens or slotted inner liners used for sand control.

According to the present invention, these objectives are achieved by observing a substantial increase in the production of sand flowing into an oil, Water or gas well having a sand control device mounted therein thereby indicating a damaged sand cont-rol device. The exact location of the damage is ascertained and a repair patch is run down the tubing string of the Well and expanded against the inside of the sand control device adjacent the damaged portion thereof thereby sealing the damaged portion.

The well may be stimulated at any time so as to clean out any casing perforations therein. The repair patch may be blank or, alternatively, it may be slotted so as to allow fluid to pass therethrough while excluding sand therefrom.

BRIEF DESCRIPTION OF THE DRAWING FIGURE l is a vertical sectional view of a cased well having a sand control device in the form of a wirewrapped screen mounted therein;

FIGURE 2 is a view similar to FIGURE 1 showing the preferred method of locating a hole in the screen of the well of FIGURE 1;

FIGURE 3 is a view similar to FIGURE 1 showing the preferred method of patching the hole in the screen ofthe well of FIGURE 1;

FIGURE 4 is a View of the damaged portion of the Well of FIGURES 1 and 2 after patching; and

FIGURE 5 is an alternative view of the damaged portion of the well of FIGURES l and 2 after patching.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT Although the invention will be described hereinbelow with reference to a Wire-wrapped screen as a sand control device, the teachings of this invention may be applied to any damaged sand control device capable of being patched in accordance with the teachings of the invention, as for example a wire-wrapped slotted liner used for gravel packing operations from which it is believed gravel has been lost and therefore the retention ability of the gravel itself no longer exists.

Referring now to the drawings, FIGURE 1 shows a Well borehole 11 extending into a subterranean oil water and/or gas formation 12. Well borehole 11 may be a single well or one of a plurality of wells drilled into formation 12 for recovering hydrocarbons therefrom, as is well known in the art. Well borehole 11 is cemented and preferably includes a casing 13 also as is well known in the art. For convenience of illustration, all wellhead components not necessary to the understanding of the invention have been omitted in FIGURES l through 4.

In accordance with the invention, well borehole 11 is provided with a sand control device, such as a plurality of vertically extending horizontally spaced wire-wrapped slots forming a screen 14 which screen preferably depends from the lower end of casing 13 as illustrated in FIGURES 1 through 4.

As illustrated in FIGURE 1, a hole 15 has been eroded in screen 14. This is observed by comparing the normal production of sand flowing from a well in the well fluid lwith a later substantial increase in the sand output from a well within a short span of time, or when a device such as a bailer is run into a well which will no longer produce and 'sand is recovered. Obviously, a plurality of such holes may be located elsewhere in screen 14. The exact location of these holes or, more particularly, hole 1S, is determined by Ameans well known in the art. For example, referring now to FIGURE 2, a wireline caliper tool 16 having feelers 17 of such a size as to avoid the screen openings or liner slots of the screen 14 is run through a tubing string 18 disposed in well borehole 11 to exactly locate the point of failure of screen 14 (i.e., the position lof hole in device 14). One such caliper tool is manufactured by J. C. Kinley Co., of Houston, Tex., and described on page 2959, Composite Catalog of Oil Field Equipment and Services, 27th revision, published by World Oil. Since the various features of tool 16 of FIGURE 2 are identical to those of the tool in the aforementioned catalog, these features have been omitted in FIGURE 2 for convenience of illustration. Feelers 17 of tool 16, as illustrated in FIGURE 2, are wide enough so as to avoid the liner slots or screen openings of screen 14 yet detect the existence of any anomalous holes in screen 14. Another technique for locating the hole is to use conventional impression packer, such as that manufactured by Lynes, Inc., of Houston, Tex.

Caliper tool 16 may, but not necessarily, includes direction indicating means 19, xed to its upper end, such as a gyroscopic compass orsimilar instrument well known in the well surveying art, for indicating the location where caliper tool 16 contacts hole 15 in screen 14. The tool 16 and indicating means 19 may be raised and lowered in well borehole 11 by means of a cable or rod 20 of sufiicient strength to raise and lower the instruments and this rod or cable may also include the necessary electrical components for coupling the instruments to a surface control unit (not shown).

It is noted that the presence of one or two holes 15 in the sand control device 14 would indicate that most of the perforations in the sand control device 14 are plugged and must be cleaned out Iwith acid. A preferred acidic composition for cleaning out device 14 is a mixture of 12% hydrochloric acid and 3% hydrofluoric acid. 1f a plurality lof the perforations in the device 14 become plugged thereby leaving only one or two perforations open, the hydrocarbons produced from the formation 12 would jet through the open perforations and against device 14 and quickly Wear a hole in it. These perforations may be cleaned out either before or after patching as will be discussed further hereinbelow.

After withdrawing caliper tool 16 from well borehole 11, a corrugated repair patch 22 is run down the tubing string 18 and expanded against the inside of the sand control device 14 over the hole 15 therein. This may be accomplished by lowering a casing patch tool 21 down tubing string 18 in the manner discussed previously concerning caliper tool 16 and illustrated in FIGURE 3. A suitable patch tool may be the casing patch tool discussed on page 2332 of the aforementioned Composite Catalog which shows a convoluted or corrugated patch which is run down a tubing string and set in a screen and expanded by running a mandrel down the patch. The apparatus is manufactured by the Halliburton Company of Dallas, Tex.

Prior to running the repair patch 22 into the well borehole 11, gravel produced from behind the screen device 14 may be replaced by pumping gravel out through the erode hole 15 by (l) straddling the hole Kwith conventional straddle packers connected t-o a small tubing string, (2) placing a packer immediately above the eroded hole, or (3) pumping gravel down the well tubing 18.

Once the patch 22 is aligned with the hole 15 in screen 14 by reference to the information obtained previously, the tool 21 is run down inside of corrugated patch 22 to expand the corrugations and thus paclcolf the failure 4 (i.e., hole 15) and place a patch over hole 15. Thus, in operation, the patch 22 is expanded against the inside of screen 14 over the hole 15 therein.

Sealing is obtained from the plastic coating on the exterior of the patch 22 as discussed in the Halliburton device, page 2332 of the Composite Catalog. The patch 22 is cold-formed and bonded against the wall of screen 14. The inflatable packers of Lynes, Inc. may be used to expand the corrugated patch 22 out against the wall of the screen 14, if desired.

As illustrated in FIGURE 4, the patch 22 is imperforate and has been placed over hole 15 in accordance with the teachings of the invention. This patch, if desired, may be slotted or perforated as illustrated in FIGURE 5 Awherein a patch 23 is shown having slots or perforations 24 to provide sand control abilities through the patch itself. Such slots or perforations may be formed as a result of a wire-wrapped patch itself.

After patching, the well may be stimulated with acid as discussed hereinabove so as to clean out the perforations.

It is within the scope of the present invention to apply the same concept to other types of sand control devices capable of being patched in accordance with the teachings of the invention. For example, in addition to the slotted casing type of screen, other types of screens or orifice members, such as Screen discs, may be patched as disclosed hereinabove.

Referring now to FIGURE 6 wherein like numerals refer to like parts of FIGURES 1 through 5, a cemented casing 26 is shown extending the full length of well borehole 11. Casing 26 is perforated at perforations 27 as is well known in the art. The screen 14 is run down` inside casing 26, then preferably gravel-packed in place. Alternatively, the annular space between screen 14 and casing 26 may or may not contain gravel, as desired. The observation of any sand plugging tubing string 18 would indicate a damaged screen 14. The method of patching hole 1S in screen 14 is similar to that discussed hereinabove. Thus, further comment would appear to be unnecessary.

I claim as my invention:

1. A method for controlling sand in a well having a tubing string and damaged sand control device mounted therein, said method comprising the steps of:

observing a substantial increase in the production of sand flowing into a well having a sand control de- Vice mounted therein thereby indicating a damaged sand control device;

determining and recording the exact location of the damage in said sand control device; running a sand con-trol device repair patch down said tubing string to a point adjacent the predetermined damaged portion xof the sand control device, and

sealing said damaged portion by expanding said patch against the inside of the sand control device adjacent the damaged portion thereof.

2. The method of claim 1 including the step of stimulating the well so as to clean out any perforations therein after patching said sand control device.

3. The method of claim 1 wherein the step of running a patch down said tubing string includes running an imperforate convoluted patch.

4. The method of claim 1 wherein the step of running a patch down said tubing string includes running a convoluted patch down said tubing string slotted so as to allow fluid to pass therethrough while excluding sand therefrom.

5. The method of claim'll including the step of stimulating the Well so as to clean out any perforations therein before patching said sand control device.

`6. The method of claim 1 wherein the step of determining and recording the exact location of the damage in the sand control device includes the steps of running, down said tubing string, a wireline caliper tool having feelers of such size as to avoid the openings in said sand control device until an anomalous open ing in said sand control device is located; and

recording the exact location of said anomalous opening thereby indicating a damaged portion of said sand control device.

7. The method of claim 1 wherein the step of expanding said patch includes running a casing patch tool down said tubing string inside said patch to expand said patch against the predetermined damaged portion of said Sand control device.

8. The method of claim 7 wherein the step of sealing said damaged portion includes the steps of cold-forming and bonding the patch against the interior of said sand control device.

9. The method `of claim 1 including, prior to running said patch down said tubing string, the Step of replacing any gravel produced through said damaged portion of said sand control device.

10. A method for controlling sand in a well having a tubing string and damaged sand control device mounted therein, said method comprising the steps of:

observing any sand plugging the tubing string mounted in said well thereby indicating a damaged sand control device;

cent the damaged portion thereof.

References Cited UNITED STATES PATENTS l5 2,986,714 7/l959 'i 2,969,840 1/1961 3,326,293 6/1967 3,353,599 11/1967 `Clasen et al. l66-14 Killingsworth 166-15 DAudiffret et al. 166-227 X Skipper 166-14 X Swift 1-66-15 20 CHARLES E. OCONNELL, Primary Examiner IAN A. CALVERT, Assistant Examiner U.S. Cl. X.R. 

